Cardiometabolic Benefits of Potatoes Mediated Along the Gut-Vessel Axis in Adults With Metabolic Syndrome

This study is focused on assessing potential health benefits of daily consumption of potatoes, specifically its resistant starch content (i.e. nondigestible carbohydrate), on blood vessel and gut health function in adults with metabolic syndrome. It is expected that the daily consumption of potatoes for two weeks, within a diet that follows the Dietary Guidelines for Americans, will improve blood vessel function in association with decreasing gut permeability ("leaky gut") that results in the absorption of bacterial toxins that reside in the intestine. Outcomes will therefore support dietary recommendations for potatoes to support vascular and gastrointestinal health.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Endotoxemia; Endothelial Dysfunction; Postprandial Hyperglycemia; Gut Health
• Intervention / Treatment: Other: Bagel; Other: Potato

Detailed Description

Cardiovascular disease is a major public health concern in the United States, where it accounts for 1 in 4 deaths every year. Vascular endothelial dysfunction is an early event leading to cardiovascular disease and can be caused by postprandial hyperglycemia. Cardiovascular disease is also characterized by metabolic endotoxemia. Metabolic endotoxemia describes increased circulating levels of gut-derived endotoxin (lipopolysaccharide; a bacterial product derived from Gram-negative bacteria in the intestines) that results from gut barrier dysfunction, a phenomenon that is common in metabolic syndrome. Studies in animals and humans have shown that consumption of resistant starch (a type of carbohydrate found in potatoes among other foods) can help to improve vascular and gut health. This clinical trial will therefore investigate the extent to which potatoes can improve microbiota composition, alleviate metabolic endotoxemia, and improve vascular function. It is hypothesized that 2-week daily ingestion of potatoes within a diet that meets the Dietary Guidelines for Americans will limit metabolic endotoxemia by decreasing gut barrier permeability and alleviating gut dysbiosis while separately improving vascular function by limiting postprandial hyperglycemia. This study will address the following objectives: 1) define changes in gut barrier function in association with improved gut microbiota composition, increased fecal short chain fatty acid (SCFA) production, and decreased serum endotoxin, 2) define changes in postprandial glycemic responses and endotoxemia, and 3) define changes in gut hormones that promote glycemic control and changes in markers of oxidative stress in relation to improvements in endothelial vascular function, all following 2-week potato consumption. To test the hypothesis, all participants will complete a randomized cross-over trial where they will receive a potato or bagel along with a diet that meets the Dietary Guidelines for Americans for 2 weeks. They will then undergo a 2-h postprandial study to define the influence of potato consumption on vascular function, glycemic control, and endotoxin translocation. Upon completing the intervention, participants will undergo a gut permeability test, fecal samples will be collected for microbiota composition analysis, and blood samples will be collected to assess endotoxin and inflammatory markers. Upon successfully completing this study, it is anticipated that chronic consumption of potatoes will be demonstrated to be an effective dietary strategy to reduce metabolic endotoxemia, improve gut health, and improve vascular function.

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Ohio
    • Columbus, Ohio, United States, 43210
      • Ohio State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Fasting glucose 100-125 mg/dL
• Waist circumference >102 cm (men), >88 cm (women)
• Fasting triglyceride >150 mg/dL
• Fasting HDL cholesterol <40 mg/dL (men), <50 mg/dL (women)
• Non-smoker
• Non-dietary supplement user (>1-mo)
• Free of gastrointestinal disorders, cardiovascular disease, cancer
• No recent use of antibiotics or any medications affecting glycemia, lipidemia, or blood pressure

Exclusion Criteria:

• Use of anti-inflammatory agents or probiotics
• Vegetarian, gluten-intolerant, carbohydrate-restricted diet
• Alcohol intake >2 drinks/d
• >7 hours/week of aerobic activity
• Women who are pregnant or lactating or have initiated or changed birth control in the past 3-months
• Taking medications that affect blood sugar, blood pressure, blood vessel health, or inflammation
• High blood pressure or any vascular diseases
• HIV, hepatitis, or blood disorders such as hemophilia
• Gastrointestinal disorders
• Cancer (current or past history)
• Anemia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Bagel diet; Bagel consumed daily for 2 weeks	Other: Bagel; A bagel will be consumed daily for 2 weeks.
Experimental: Potato diet; Potato consumed daily for 2 weeks	Other: Potato; A potato will be consumed daily for 2 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endotoxin	Fasting serum endotoxin concentration	Day 14
Vascular Endothelial Function	Area under curve (change from baseline) for brachial artery flow-mediated dilation (FMD). The unit for FMD is %, which is calculated as: [vessel diameter in millimeters (post-occlusion) - vessel diameter in millimeters (pre-occlusion)] / vessel diameter in millimeters (pre-occlusion) x 100. FMD(%) is then used to caluclate area under the curve based on independent measures of FMD at 0-120 minutes)	Day 14 Postprandial (0, 30, 60, 90, 120 minutes)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fasting Glucose Day 0	Fasting plasma glucose	Fasting glucose on Day 0
Fasting Insulin Day 0	Fasting plasma insulin	Fasting insulin on Day 0
Postprandial Insulin	Plasma insulin concentration area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Postprandial Glucose	Postprandial plasma glucose concentration area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Fasting Endotoxin	Fasting serum endotoxin concentration	Day 0
Postprandial Endotoxin	Postprandial serum endotoxin concentration area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Postprandial Cholecystokinin	Plasma CCK area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Postprandial NOx	Plasma total nitrite/nitrate area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Fasting NOx	Fasting plasma concentration of nitrite/nitrate	Day 14
Postprandial Malondialdehyde (MDA)	Plasma MDA concentration, biomarker of oxidative stress area under curve change from baseline	Day 14 postprandial (0, 30, 60, 90, 120 minutes)
Fasting Malondialdehyde (MDA)	Fasting plasma MDA concentration, biomarker of oxidative stress	Day 14
Vitamin C	Fasting vitamin C concentration, biomarker of oxidative stress	Day 14
Fasting Glucose Day 14	Fasting plasma glucose Day 14	Fasting glucose on Day 14
Fasting Insulin Day 14	Fasting plasma insulin Day 14	Fasting insulin on Day 14
Lactulose/Mannitol Ratio	Urinary concentration of the non-digestible sugars lactulose/mannitol (mg/mg)	Day 14, 0-5 hours post-consumption of sugar probes
Sucralose/Erythritol Ratio	Urinary concentration of the non-digestible sugars sucralose/erythritol	Day 14, 6-24 hours post-consumption of sugar probes
Fecal Butyrate	Fecal concentration of butyrate	Day 14
Fecal Acetate	Fecal concentration of acetate	Day 14
Fecal Propionate	Fecal concentration of propionate	Day 14
Fasting Cholecystokinin	Fasting plasma concentration of CCK	Day 14
Fasting Vascular Endothelial Function	Fasting flow-mediated dilation of the brachial artery. Measure is calculated as: [post-occlusion vessel diameter (mm) - pre-occlusion vessel diameter (mm) / pre-occlusion vessel diameter (mm)] x 100	Day 14
cIMT	Carotid intima-media thickness. Mean thickness of left and right carotid artery intima media.	Day 14
Day 14 BMI	Body mass index calculated as kg weight per meters squared	Day 14
Day 0 Waist Circumference	Waist circumference in centimeters	Day 0
Day 14 Waist Circumference	Waist circumference in centimeters	Day 14
Day 0 Diastolic Blood Pressure	Diastolic blood pressure on Day 0	Day 0
Day 14 Diastolic Blood Pressure	Diastolic blood pressure on Day 14	Day 14
Day 0 Systolic Blood Pressure	Systolic blood pressure on Day 0	Day 0
Day 14 Systolic Blood Pressure	Systolic blood pressure on Day 14	Day 14
Day 0 BMI	Body mass index calculated as kg weight per meters squared	Day 0

Collaborators and Investigators

• Sponsor: Ohio State University
• Collaborators: Alliance for Potato Research and Education
• Investigators: Principal Investigator: Richard Bruno, PhD, RD, Ohio State University

Publications and helpful links

General Publications

• Cao S, Shaw EL, Quarles WR, Sasaki GY, Dey P, Hodges JK, Pokala A, Zeng M, Bruno RS. Daily Inclusion of Resistant Starch-Containing Potatoes in a Dietary Guidelines for Americans Dietary Pattern Does Not Adversely Affect Cardiometabolic Risk or Intestinal Permeability in Adults with Metabolic Syndrome: A Randomized Controlled Trial. Nutrients. 2022 Apr 8;14(8):1545. doi: 10.3390/nu14081545.

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2018
• Primary Completion (Actual): July 16, 2020
• Study Completion (Actual): July 16, 2020

Study Registration Dates

• First Submitted: August 2, 2018
• First Submitted That Met QC Criteria: August 8, 2018
• First Posted (Actual): August 10, 2018

Study Record Updates

• Last Update Posted (Actual): June 15, 2025
• Last Update Submitted That Met QC Criteria: June 12, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Infections; Sepsis; Systemic Inflammatory Response Syndrome; Inflammation; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Bacteremia; Toxemia; Cardiovascular Diseases; Metabolic Syndrome; Hyperglycemia; Endotoxemia
• Other Study ID Numbers: 2018H0265

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Data will be published as aggregate only. Data sharing may be possible pending institutional agreements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No